Apparatus for ammonia manufacture



May 29, F. LOPEZ APPARATUS FOR AMMONIA MANUFACTURE Filed Nov. 30. 1928 A 3 F ll Iv F E p I 0 n M A m UV m M J 0 am a o o I a 9 INVENTOR BY fieflres a Zia/78f A; ATTORNEY Patented May 29, 1934 APPARATUS FOR AMMONIA MANUFACTURE Francesco Lopez, Padova, Italy, assignor to Societa Anonima Industria Ammoniaca, Padova, Italy, a corporation of Italy Application November 30, 1928, Serial No. 322,901 In Italy March 26, 1928 8 Claims.

This invention relates to apparatus for carrythe working pressures, said casings being joined ing out chemical reactions between or upon gaseous substances, and more particularly refers to improvements in apparatus for the synthetic production of ammonia and for chemical reactions of like character.

The synthetic manufacture of ammonia from its elements hydrogen and nitrogen is usually carried out under pressures which may vary from 100 to 1000 atmospheres and at temperatures of from 400 to 600 C., in the presence of agents assisting the reaction, generally known under the name of catalyzers.

In the present state of the art, catalyzers sufficiently active for use at lower temperatures are not as yet known, so that in order to limit the harmful effects of hydrogen, at the above mentioned temperatures, upon the materials employed to withstand the working pressures used in these operations, various expediencies have heretofore been resorted to with more or less success.

Furthermore when low pressures are used, the rate of reaction is low, and the heat of reaction is therefore incapable of counterbalancing in full all the losses occurring by conduction or convection as well as those warming in the heat exchanger; so that in order to maintain a working temperature within the apparatus it is necessary to employ special arrangements in the construction of the heat exchanger and of the reaction furnace itself in order to obtain a spontaneous reaction and in order to maintain the required working temperature with the least possible quantity of subsidiary heat.

The primary object of the present invention is to provide a novel and improved apparatus for the synthetic manufacture of ammonia adapted, to conveniently answer the requirements of synthetic reactions, especially those due to the use of low pressures.

Another object of the invention is to provide a novel and improved construction of apparatus for the synthetic manufacture of ammonia, which is characterized by extreme simplicity of design and by a special arrangement of its various parts, making it possible to remove and replace any one of its parts in a relatively short time and with a minimum expenditure of labor.

My invention is illustrated by way of example in the annexed drawing, which is a sectional view in elevation of an apparatus embodying the same.

The apparatus shown consists of two superimposed cylindrical casings, A, B, adapted to resist together by a number of bolts 0, and forming two chambers separated by a steel 'plate'D. Said plate D is provided with a number of openings E through which the mixture N2+3H2 may freely the two casings the upper one represents the reaction furnace, and the lower one the heat economizer or exchanger. r All the parts enclosed within casings A and B are supported upon and carried by the plateD.

After subjecting the reacting gases tocompression up to the desired working pressure, the same are admitted within the heat exchanger A through an inlet tube 1, carried by bottom cover G. Within the exchanger these gases come in contact with a series of coils 2, within which flow the hot gases resulting from the synthetic reaction, said hot gases going through the heat exchanger in a direction opposite to that of the reacting gases.

Said coils 2 have their ends soldered or welded to two shells 3, 4, acting as distributor and collector of the reaction gases respectively. These gases are then led by tube 5 to some suitable ammonia absorption apparatus. The main feature of the heat exchanger described resides in this, that all its working parts are carried by plate D and that the coils are easily deformable under the influence of temperature changes independently of the relative positions 01 their attaching ends; so that all the parts will readily extend or contract under the influence, of the changes of temperature taking place during the operation, without impairing in the least their capacity to perform their respective functions.

The coils are made of iron or copper or other material impervious to the action of hydrogen, nitrogen and ammonia gas whether moisture is present or not, and the capacity of the coils to expand or contract is assured by their zig-zag shape which causes them to readily yield to elastic deformations due to said expansion or contraction.

The gases passing through the heat exchanger A are admitted to the upper chamber B which constitutes the reaction furnace proper, by openings E, and are then compelled to travel through a sinuous path before they reach the catalyzing tube 9 inserted within the reaction chamber'8.

To this end the gases are first forced to pass through an annular passage interposed between the inner surface of casing B and a tubular member 6, upwardly extending from plate D. The gases are then made to pass between the inner surface of tubular member 6* and the outer surface of a tubular member '7, downwardly projecting from a cover plate L. During the course of their travel, the temperature. of the gases gradually increases at the expense of the heat of conduction and convection originating in the reaction chamber.

When the gases reach the lower edge of tubular member '7 their course is once more reversed, and they travel upwardly through an annular passage interposed between the inner surface of tubular member 7 and the outer surface of the reaction chamber 8, which has the form of a cylindrical shell with a funnel shaped lower end secured to the upper end of the tubular member 10 carried by and extending through the center of plate D.

In the annular space between tubular member 7 and reaction chamber 8 is placed an electric heating element by means of which the gases may be brought to a temperature slightly less than the active temperature of the catalyzer.

Tube 9 containing the catalyzer, within which the reaction proper occurs, has a flanged upper end provided with a series of openings H leading from the inside of the tube to the annular chamber between member 7 and chamber 8, and through these openings the hot gases are admitted to the catalyzing tube. In going through the same, the gases react with each other and are then discharged through tube 10 within shell or collector 3 and then through the coils of the heat exchangers.

The main feature of the arrangement described is that all its parts are attached at one end only, so that they can readily respond to the expanding or contracting influences due to temperature changes.

Another important feature is the arrangement for securing a catalyzing tube in position, insuring an absolutely tight connection and at the same time permitting the ready removal and replacement of the catalyzer.

It is seen from the drawing that the renewal of the catalyzing material within the catalyzing tube may be easily effected after the removal of the cover F, by releasing bolts I which maintain cover plate L in position. Said cover plate L together with the upper flange of chamber 8 clamps in position the upper flange of the catalyzing tube, and the tightness of the arrangement is insured by a packing M, so that the gases are prevented from passing through the annular space between the inner surface of member 8 and the outer surface of catalyzing tube 9.

After removal of cover plate L, tube 9 can easily be extracted and the catalyzing material within the same may be renewed, or else a new catalyzing tube may be inserted.

Coverplate L carries a tubular shell 11 extending within the catalyzing tube, acting as a shield for the thermo-electric couples which are used to control the temperature within the reaction chamber proper. Said thermo-electric couples pass through plug N carried by cover plate L and are connected to terminals 0 which are of a design similar to the terminals P of the heating element.

It will be seen that all the elements within the reaction furnace are also carried by plate D, and that the same are easily removable and replaceable within a relatively short time.

The details of construction of my invention may vary to a certain extent from those shown without departing from the inventive idea; the drawing will therefore be understood as being intended for illustrative purposes only, and not in a limiting sense.

I accordingly reserve myself the right to carry my invention into practice in all those ways and manners which may enter, fairly, into the scope of the appended claims.

I claim:

1. In apparatus of the class described, a reaction unit comprising a casing, a tubular reaction chamber within said casing, a plurality of radially spaced tubular elements coaxial therewith, providing a sinuous path for gases admitted to said casing, from the point of admission to said reaction chamber, said chamber and tubular elements being fixed at one end only to said casing, so as to be freely deformable when temperature changes occur, a removable cover for said chamber, and a flanged tubular catalyst container inserted within said chamber, the flange of said container being clamped between said cover and the edge of said chamber.

2. Apparatus of the class described, consisting of a reaction unit comprising a casing, a heat exchanging chamber arranged end to end therewith, a partition interposed therebetween having inlets permitting gases to flow from said heat exchanging chamber into said casing, a tubular reaction chamber within said casing, a plurality of radially spaced tubular elements coaxial therewith providing a sinuous path for gases admitted to said casing from the point of admission to said reaction chamber, said chamber and tubular elements being all fixed at one end only so as to be easily deformable when temperature changes occur, and discharge means for said reaction chamber, mounted within said heat exchanging chamber.

3'. Apparatus of the class described, consisting of a reaction unit comprising a casing, a heat exchanging chamber arranged end to end therewith, a partition interposed therebetween having inlets permitting gases to flow from said heat exchanging chamber into said casing, a tubular reaction chamber within said casing, a plurality of radially spaced tubular elements coaxial therewith providing a sinuous path for gases admitted to said casing from the point of admission to said reaction chamber, said chamber and tubular elements being fixed at one end only to said partition so as to be easily deformable when temperature changes occur, and discharge coils for said reaction chamber, extending within said heat exchanging chamber, said coils also being easily deformable under the influence of temperature changes.

4. Apparatus of the class described, consisting of a reaction unit comprising a casing, a heat exchanging chamber arranged end to end therewith, a partition interposed therebetween having inlets permitting gases to flow from said heat exchanging chamber into said casing, a tubular reaction chamber within said casing, a plurality of radially spaced tubular elements coaxial therewith providing a sinuous path for gases admitted to said casing from the point of admission to said reaction chamber, said chamber and tubular elements being fixed at one end only so as to be easily deformable when temperature changes occur, a removable cover for said reaction chamber, a catalyst container removably inserted within said reaction chamber, and bent discharge coils for said reaction chamber, mounted within said heat exchanging chamber.

5. Apparatus of the class described, consisting of a reaction unit comprising a casing, a heat exchanging chamber arranged end to end therewith, a partition interposed therebetween having inlets permitting gases to flow from said heat exchanging chamber into said casing, a tubular reaction chamber within said casing, a plurality of radially spaced tubular elements coaxial therewith providing a sinuous path for gases admitted to said casing from the point of admission to said reaction chamber, said chamber and tubular elements being fixed at one end only to said partition so as to be easily deformable when temperature changes occur, a removable cover for said reaction chamber, a flanged tubular catalyzers container inserted within said reaction chamber, the flange of said container being clamped between said cover and the edge of said chamber, and discharge coils for said reaction chamber, extending within said heat exchanging chamber.

6. Apparatus of the class described, consisting of a reaction unit comprising a casing, a heat exchanging chamber arranged end to end therewith, a partition interposed therebetween having inlets permitting gases to flow from said heat exchanging chamber into said casing, a tubular reaction chamber within said casing, a plurality of radially spaced tubular elements coaxial therewith providing a sinuous path for gases admitted to said casing from the point of admission to said reaction chamber, said chamber and tubular elements being removably fixed at one end only so as to be easily deformable when temperature changes occur, and bent discharge coils for said reaction chamber, mounted within said heat exchanging chamber.

7. Apparatus of the class described, consisting of a reaction unit comprising a casing, a heat exchanging chamber arranged end to end therewith, a partition interposed therebetween hav' ing inlets permitting gases to flow from said heat exchanging chamber into said casing, a tubular reaction chamber within said casing, a plurality of radially spaced tubular elements coaxial therewith providing a sinuous path for gases admitted to said casing from the point of admission to said reaction chamber, said chamber and tubular elements being removably fixed at one end only to said partition so as to be easily deformable when temperature changes occur, a removable cover for said reaction chamber, a flanged tubular catalyzers container inserted within said reaction chamber, the flange of said container being clamped between said cover and the edge of said chamber, a plurality of zig-zag coils, extending within said heat exchanging chamber, leading the reaction products from said reaction chamber to a point of discharge, and means for admitting the reacting gases to said heat exchanging chamber.

8. In apparatus of the class described, a reaction unit comprising a casing, a heat exchanging chamber arranged end to end therewith, a partition interposed between said heat exchanging chamber and said casing, having inlets permitting gases to flow from said heat exchanging chamber into said casing, a tubular reaction chamber carried by said partition within said casing, a plurality of radially spaced tubular elements within said casing, providing a sinuous path for said gases from the point of admission to said reaction chamber, a discharge outlet through said partition for said reaction chamber, a detachable hermetic connection between said reaction chamber and said outlet, a removable cover for said reaction chamber, a catalyst container removably inserted within said reaction chamber, a plurality of discharge coils, mounted Within said heat exchanging chamber, leading the reaction products from said outlet to a point of discharge, and means for admitting the reacting gases to said heat exchanging chamber.

FRANCESCO LOPEZ. 

